Because according to them they want to stop digital crime, control ransom demands, crack down on deep web activities and also as they cannot get control over it (because it is controlled by no one), so everyone is trying to regulate it.

But eventually everyone will fail.

I believe regulating Bitcoin will ultimately increase black market of Bitcoin. (it will get more worse). And their stupid policies will also hamper innovation.
But don’t worry.

The revolution has begun. It is gradually overtaking the whole world. Time is not far when the whole system goes through a shift. (Shift of power, decisions), the decentralized economy will bring new hope, that will be the world with actual democracy, where power will literally be in hands of everyone. There will be no governments, no authority, but a more developed and decentralized system and more control.
And no one can stop it.